1. Field of the Invention
The invention relates to a machine for the processing of foodstuffs or for the preparation of liquid or pasty pharmaceutical and chemical products.
2. Discussion of the Related Art
In preparation of foodstuffs, pharmaceuticals or chemical products, it is well known to provide a machine having a bowl and a motor shaft which protrudes perpendicularly through the bowl bottom and into the bowl. Typically, this motor shaft can be driven at high speed by a motor arranged beneath the bowl and is adapted to receive a sleeve-shaped tool carrier which is rotatably fixed but releasable at its upper free end. The sleeve-shaped tool carrier also has radially extending tools at its lower end.
An example of such a machine is disclosed in German Gebrauchsmuster 88 09 812.5. In such processing machines, sometimes minimal amounts of a product must also be prepared with satisfactory quality, a minimal amount here meaning, for example, approximately one thirtieth of the gross content of the bowl. With a bowl having a content of 5 liters, an amount of 0.17 liters would therefore represent a minimal amount. To produce the products described above it is particularly important that, when working or mixing constituents of a formulation, they can be processed at speeds of about 300 to 3000 rpm. When using previously known tools, due to the design of these tools and with the effect of the centrifugal forces, the constituents of the formulation are often sprayed onto the bowl wall and consequently can no longer be automatically mixed to form the required minimal amount. This requires a frequent opening of the bowl cover in order to scrape off the bowl wall, causing the preparation process to be prolonged. Obviously, this is never desirable and in many cases will be entirely unacceptable.
With previously known machines, it has also proven largely impossible with such minimal amounts to achieve adequate mixing since the revolving tools will not reach the material on the bowl bottom. This problem arises in particular when mixing highly pasty or highly viscous materials. However, this problem does not occur with previously known machines if the bowl is filled at least up to one third of its capacity, since an adequate turbulence and a pressure of the product in the direction of the bowl bottom can then be generated.